Delta said Tuesday that it increased flying capacity by 0.7 percent. A 1.4 percent rise in domestic capacity offset a 0.4 percent decline in international capacity.

Occupancy on its planes rose 0.7 percent. However, domestic occupancy fell 0.9 percent because Delta added more seats than passengers on those flights.

The airline completed 99.9 percent of its scheduled flights in May as it benefited from efforts to improve its operations as well as benign weather.

For the year so far, Delta traffic has fallen 0.2 percent, while capacity is down 1.3 percent. Occupancy is up 0.9 percent.

Also Tuesday, Delta CEO Richard Anderson was named chairman of the International Air Transport Association trade group. It's a one-year appointment which is effective immediately, the group said. IATA also said that Air Canada President and CEO Calin Rovinescu will be its chairman beginning in June 2014.

Shares of Delta Air Lines Inc. rose 22 cents to $18.03 in early trading.